When an object is typically opened on the monitor of a computer, the name of the object is input via a keyboard to open it. An "object" used herein is intended to mean a combination of data and the access means therefor. After a directory (of registered objects) has been displayed, any of the registered objects may be selected by entering a command. Further operations to be performed after the object has been opened are also typically input via keyboard. In many cases operations such as this are difficult to handle unless an operator has detailed knowledge of the application, e.g., through a technical manual. This has limited the number of people willing and able to work with computers.
More recently, as a supplement to a keyboard, there has recently been developed a so-called graphical user interface (GUI) in which an object can be opened and closed and commands can be input by using a "mouse" device. The mouse is usually connected through a wire to the computer. The mouse may be moved on a board thereby moving a cursor on the monitor of a computer. A typical GUI also utilizes icons which represent an object and are displayed on the monitor. Thus the mouse may be used to select an object displayed on the monitor and perform limited operations on it. GUIs have greatly simplified computer operations for the average user. In addition, a wireless mouse has recently been developed, thereby expanding the operational range and enhancing operability.
However, in the above-described conventional mouse (including wireless mice, the pointer (which is used to select an object and normally displayed as an arrow) on the monitor is moved and only the function of the object selected by the pointer is performed, so the mouse is limited to acting as a simple input device.
For example, when you actually do work (for example, when you telephone), the actual work of operating the telephone is not connected to the act of opening an object on a computer and viewing the data content of the object, in a case where the data (e.g., telephone directory) required of this work have been registered as objects on a computer.
One proposal has been to project each icon of objects to be displayed on the monitor of a normal computer with the use of a TV projector or liquid crystal overhead projector (OHP) device, to provide a pointing device movable on a work table, and to put the pointing device on a projected image to open the object (reference: Pierre Wellner, "The Digital Desk Calculator and Tangible Manipulation on a Desk Top Display," ACM, UIST'91, Nov. 11-13, 1991). In this case however, as before, the pointing device is limited to conventional input functions.
Consider, for example, the context of a museum wherein a conventional computer system is installed. Data on exhibits are classified, a password may be set for each classification. A one-way information provision may be made such that data is output after input of the password by the visitor. However, this method has not come to meet requirements such that visitors can interactively access the data on the computer. Thus, even in these days where words such as "multi-media" and "virtual reality" have been recited like the buzzwords of the times, the realization of connecting a computer to more realistic work has been difficult.